India doesn't have the basic infrastructure to handling manufacturing at a reasonable level. A milling plant is, I would say, completely out of the question.
The Wistron plant is in Bangalore, India. It's supposed to be a tech hub. Based on data from the Bangalore Electricity Supply Company, the city experienced
1,200 incidents of unscheduled power outages in January 2019 alone. Since the start of February, there have already been 250 incidents.
https://www.bescom.org/upo/public.php
Compare that to Shenzhen, they have 16,000 buses and 20,000 taxis, all of which are electric. The infrastructure is there and can fully support manufacturing.
I think we will continue to see local assembly in India, but it will be limited to their domestic market for a long time.